He instantly regretted taking apart the laptop after realizing how many complex components there were inside.

Tom and Mary said they regretted not following John's advice.

Tom messaged Mary a fallacious article on margarine and regretted it afterwards.

He regretted lying to her.

Tom said that he regretted his decision to do that.

I spent all I had in order to buy it, but I never regretted doing so.

Mary regretted quitting her job.

Ziri soon regretted that.

They regretted quitting their jobs.

Tom said he regretted his decision.